Services that broadcast or deliver signals having continuity, such as video signals of news or sports programs, via Internet Protocol (IP) networks (hereinafter simply referred to as IP networks) have been widely used in recent years. In such services, any dropout in a video signal being broadcast or delivered is not preferable, since end users may directly view the video being delivered via the IP network.
In view of this, there is proposed an encoding system that is equipped with a plurality of encoders for compressing a video signal as the video signal is output from a video information source such as a camera or a video editing apparatus, and that compresses the video signal by using one of the encoders (for example, refer to Japanese Laid-open Patent Publication No. 2011-217137).
For example, the encoding system disclosed in Japanese Laid-open Patent Publication No. 2011-217137 includes a working encoder and a standby encoder arranged in series. In this system, normally a video stream is encoded by the working encoder, and the encoded video stream is then temporarily buffered in the standby encoder and thereafter transmitted out onto a transmission line. In the event of failure of the working encoder, the video stream is input directly into the standby encoder which then encodes the video stream and transmits the encoded video stream onto the transmission line. In this case, the standby encoder compares the buffered video stream and the directly input video stream to identify the position at which the transmission of the video stream was interrupted due to the failure of the working encoder, and resumes the transmission of the video stream from the interrupted position. With this arrangement, even when a failure occurs in the working encoder, any dropout can be prevented from occurring in the video stream being transmitted out on the transmission line.